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| Titel |
Long-path averaged mixing ratios of O3 and NO2 in the free troposphere from mountain MAX-DOAS |
| VerfasserIn |
L. Gomez, M. Navarro-Comas, O. Puentedura, Y. González, E. Cuevas, M. Gil-Ojeda |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1867-1381
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| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Measurement Techniques ; 7, no. 10 ; Nr. 7, no. 10 (2014-10-07), S.3373-3386 |
| Datensatznummer |
250115924
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| Publikation (Nr.) |
 copernicus.org/amt-7-3373-2014.pdf |
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| Zusammenfassung |
| A new approximation is proposed to estimate O3 and NO2 mixing
ratios in the northern subtropical free troposphere (FT). The proposed
method uses O4 slant column densities (SCDs) at horizontal and
near-zenith geometries to estimate a station-level differential path. The
modified geometrical approach (MGA) is a simple method that takes advantage
of a very long horizontal path to retrieve mixing ratios in the
range of a few pptv. The methodology is presented, and the possible
limitations are discussed. Multi-axis differential optical absorption
spectroscopy (MAX-DOAS) high-mountain measurements recorded at the
Izaña observatory (28° 18' N, 16° 29' W)
are used in this study. The results show that under low aerosol loading,
O3 and NO2 mixing ratios can be retrieved even at very low
concentrations. The obtained mixing ratios are compared with those provided
by in situ instrumentation at the observatory. The MGA reproduces the
O3 mixing ratio measured by the in situ instrumentation with a
difference of 28%. The different air masses scanned by each instrument
are identified as a cause of the discrepancy between the O3 observed by
MAX-DOAS and the in situ measurements. The NO2 is in the range of 20–40 ppt,
which is below the detection limit of the in situ instrumentation, but
it is in agreement with measurements from previous studies for similar
conditions. |
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